1. Analysis of total T cells and T cell subsets with monospecific T cell reagents (developed with the hybridoma technique) in both lymphomas of T cell lineage and B cell lymphomas with minor populations of T cells (nodular lymphoma, in particular). 2. Utilization of the fluorescence-activated cell sorter (FACS) to define B cell subsets in lymphomas of B lineage by quantitation of surface immunoglobulin. The increased sensitivity of the FACS will also allow identification of some B cell neoplasms not recognized with the fluorescence microscope. 3. Development of a comprehensive classification of human lymphoma based on the identification of B and T lineage and subset specificity. 4. Correlation of cell surface phenotype with the microscopic appearance (pathology) and clinical parameters including presentation, course, response to treatment and survival. 5. Adaptation of these novel surface marker methods to routine clinical application in lymphoma and lymphocytic leukemia.